ST. PAUL, Minn., Sept. 2 -- Alaska Gov. Sarah Palin was not subjected to a lengthy in-person background interview with the head of Sen. John McCain's vice presidential vetting team until last Wednesday in Arizona, the day before McCain asked her to be his running mate, and she did not disclose the fact that her 17-year-old daughter was pregnant until that meeting, two knowledgeable McCain officials acknowledged Tuesday.

Palin was one of two finalists in the vice presidential sweepstakes who were interviewed last week by former White House counsel Arthur B. Culvahouse Jr., just days before McCain introduced her to the nation as his choice. The other finalist was Minnesota Gov. Tim Pawlenty. One of the officials said Culvahouse was chasing down last-minute information about Pawlenty at the request of the campaign as late as last Thursday, the day McCain offered the job to Palin and she accepted.

The new details of the selection process provide a fuller picture of how and when McCain made his decision. Despite the late interview of the little-known Palin, senior McCain advisers said Tuesday night that she was chosen only after a lengthy and deliberative process that included the same background investigation given to others on McCain's shortlist and considerable debate among the candidate's inner circle about all his choices.

McCain did not speak face to face with Palin until Thursday morning, at his retreat in Sedona, Ariz. He also talked to her by telephone the previous Sunday. McCain had spoken with all of the others on his shortlist over the course of a selection process that went on for several months, but he was least familiar personally with the person he finally chose.

Palin flew to Arizona last Wednesday and met with senior McCain advisers Steve Schmidt and Mark Salter that night in Flagstaff. What had not been known previously was that she had met earlier the same day with Culvahouse.

McCain advisers said they had gathered extensive information about Palin before that meeting, including details of an ongoing investigation in Alaska involving her firing of the state's public safety commissioner. Details of her life and her record as governor that have since emerged in media accounts were discovered during that process, they said.

Palin, along with other finalists, completed a lengthy questionnaire that probed many personal issues. Campaign officials declined Tuesday to respond to questions about whether she had returned the questionnaire to the vetting team before she arrived in Arizona, saying they would not provide details of the timing of the process.

McCain officials said that questionnaire and the personal interview revealed three new facts previously unknown to the team: Palin's daughter's pregnancy, the arrest of her husband two decades ago for driving while intoxicated, and a fine Palin paid for fishing without proper identification.

"We made a political determination that the American people would not object to a female candidate with a 17-year-old daughter who was pregnant," Schmidt said Tuesday. "We believed that parents all over America would understand that life happens. The team made a recommendation to the senator that these issues were not disqualifying."

Schmidt also said the campaign had made a decision much earlier not to announce McCain's running mate until the day after the Democratic convention ended. He said McCain's team had long planned to use all the time available to weigh the choice. He dismissed questions that the campaign had made a hasty or ill-informed decision in the selection.

"Throughout this deliberative process of selecting a vice president, John McCain's political advisers each argued pro and con positions to the senator about each of the finalists for his consideration," he said. "The senator had an opportunity to reflect on all the pro arguments for each nominee and all of the con arguments for each nominee."

The search process started in the spring. McCain's vetting team was given a list of 20 names and Culvahouse's group prepared lengthy background books on each candidate, based primarily on a search of public records. Ultimately, the list of 20 was pared to six serious finalists, then to two, and finally to Palin. According to several campaign sources, Palin was on the list from the start.

In addition to Palin and Pawlenty, the four other finalists are believed to have been Sen. Joseph I. Lieberman, the Democrat-turned-independent from Connecticut; former Pennsylvania governor Tom Ridge; former Massachusetts governor Mitt Romney; and Louisiana Gov. Bobby Jindal.

All six were subjected to a lengthy background investigation that included a review of tax returns dating back seven years, a credit check, and a 70-item questionnaire that addressed nannies and household employees, infidelity, payment for sex, treatment for drug or alcohol abuse, and other personally intrusive subjects.

Last weekend, two campaign officials told The Washington Post that the background investigation of the finalists included an FBI check of any possible ongoing criminal investigations. That information was incorrect. A knowledgeable official said Tuesday that the vetting team had hoped to run such a check but that FBI officials declined to do so because that type of inquiry is reserved for people nominated for senior administration jobs. The official also said the FBI was uncomfortable providing the information to a political campaign, rather than to government officials.

One U.S. law enforcement official, who spoke on the condition of anonymity because of the sensitivity of the issue, said the FBI does not conduct any kind of background checks or criminal history searches on behalf of political candidates or parties.

Culvahouse's personal interviews of the prospective vice presidential candidates included other questions as well. Among them: If the CIA were to report that Osama bin Laden had been identified in the frontiers of northern Pakistan, but that an attempt to kill him would result in civilian casualties, would the person authorize such an action? If Democratic National Committee Chairman Howard Dean announced that he was holding a news conference with a mystery person to reveal damaging information about the candidate, who would they most fear it would be?

Palin's firing of Walt Monegan, Alaska's public safety commissioner, after he refused to fire a state trooper who had been married to her sister, and a probe surrounding that action, has become one of the key questions about her background.

The vetting team turned up relevant information during the review of public records, but at Culvahouse's direction, they investigated the matter at length. The matter was also part of the three-hour interview Culvahouse conducted with Palin. "We spent a lot of time on the Monegan thing," said one McCain official. "So that was one that was absolutely no surprise."

Rick Davis, McCain's campaign manager, said the trooper allegations were made in a "highly charged political environment" in which Palin has battled with fellow Republicans for years. He said a full inquiry will back up Palin's complaints about what he called "heinous acts" by the trooper.

A bipartisan panel of the Alaska legislature is investigating whether Palin tried to pressure the commissioner -- and eventually removed him from office -- for failing to fire her former brother-in-law from the state police force.

Palin denies the allegation, saying she had merely alerted officials of concerns about her former brother-in-law, who was going through a bitter divorce with her sister. Palin said she witnessed dangerous behavior from him that prompted her to act. Lawmakers are trying to determine whether her subsequent decision to fire the commissioner was the result of his unwillingness to remove the trooper from his job.

Through the course of the process of picking a vice president, McCain met with his political team about half a dozen times for extensive discussions and debate. That group included Davis, Schmidt, Salter and senior adviser Charlie Black. McCain's wife, Cindy, also played an influential role, aides said. One lengthy meeting was held in Aspen, Colo., in mid-August.

But the final stages did not occur until last week as the self-imposed deadline loomed. Aides had said earlier that Palin was invited to meet McCain in Arizona only after she appeared to be a likely choice, barring something unforeseen in her interview with the candidate. But what they had not said was that Culvahouse had not yet conducted his interview until that time as well.

"From the beginning, Senator McCain knew he had until Thursday to make a final decision," Schmidt said. "The process was anything but rushed and hurried."

But another official said the "process almost by definition is going to be back-end-loaded."

"We expected the last two weeks after Senator Obama made his selection to be pretty frantic," the official said.

Staff writers Michael D. Shear in St. Paul and Dan Eggen in Washington contributed to this report.